Evaporator for refrigerating machines



Dec. 15, 1936.

F. T. GROTHOUSE 2,064,659

EVAPORATOR FOR REFRIGERATiNG MACHINES Filed Feb. 2, 1955 InQentor: FranK T Groth use,

. 8.6 by g Attorney- Patented Dec. 15, 1936 UNITED nvarona'roa FOR REGEEAG MAS Frank '1. Grothouse, Fort Wayne, ind, assignor to General Electric Company, a coration of New York Application February 2, 1935, Serial No. 4,653

16 Claims.

My invention relates to evaporators of the hooded type for refrigerating machines.

Evaporators of the flooded typeusually include a header and an extended refrigerant passage communicating therewith. Liquid refrigerant is supplied to the evaporator from a compressor and condenser unit, or other refrigerant liquefying apparatus. Such liquid refrigerant passes through the refrigerant passage and is vaporized by the absorption of heat from articles to be cooled, which are contained in a compartment in which the evaporator is located. In many types of refrigerators, particularly in those designed for household use, the evaporator is ordinarily provided with a freezing compartment located in or adjacent the main food storage compartment. Such evaporators are preferably constructed of sheet metal both because of the low manufacturing cost, and also because of the pleasing appearance of the finished product. When such evaporators are constructed of sheet metal the header and refrigerant circulatory passages may conveniently be formed by indentations in one or both of the complementary sheet metal portions making up the evaporator.

It is an object of my invention to provide an evaporator of the flooded type for refrigerating machines including a plurality of headers and a refrigerant circulatory passage communicating therewith so arranged that they occupy a minimum amount of the usable storage space in the enclosure formed by the evaporator, and yet ef-.

fectively utilize the evaporator surfaces for the transference of heat from articles to be cooled.

It is a further object of my invention to provide an improved sheet metal evaporator for refrigerating machines made up of complementary portions of sheet metal and forming at least three side walls of a freezing compartment.

Further objects and advantages of my invention will become apparent as the following description proceeds and the features of novelty which characterize my invention will be pointed out with particularity in the claims annexed to a and forming a part of this specification.

For a better understanding of my invention, reference may be had to the accompanying drawing in which Fig. 1 is a front elevation of a portion of a refrigerating machine, the; refrigerating machine including an evaporator embodying my invention; Fig. 2 is a perspective view of an evaporator embodying my invention; Fig. 3 is a sec- 'tiona1 view onthe iine 3-3 of the evaporator shown in Fig. 2; and 4 is a schematic repre- (ci. est-126) sentation of the refrigerant circulatory system of the evaporator shown in Fig. 2.

Referring to the drawing, in Fig. 1 I have shown a refrigerating machine including an evaporator embodying my invention. In this refrigerating machine a motor and compressor are arranged in a hermetically sealed casing it. Gaseous refrigerant is compressed by the rotor driven compressorin the casing iii and is discharged into a natural draft air cooled condenser H where it is liquefied. The liquefied refrigerant flows from the condenser II i through a flow controlling float valve i2 into a liquid line l3, which supplies liquid refrigerant to an evaporator M. The evaporator It comprises a horizontal U-shaped body made of two sheets or portions of sheet metal l5 and 86, preferably of steel, welded together with their adjacent surfaces in contact and forming vertical side walls of the evaporator id. Complementary indentations ii and iii 'in the sheets 85 and i6, respectively, form a horizontal cylindrical header H9 in one.of the side walls of the freezing 'compartment formed by the evaporator it. Horizontal cylindrical headers 26 and 2! are formed in the remaining side walls of the evaporator M by complementary indentations in the sheets l5 and it similar to the indentations ii and id. The headers it, 20, and 2| are in substantial horizontal alinement and are connected in series above the level of liquid refrigerant therein by. pressure equalizing passages 22' and 23 formed by indentations in the exterior sheet it. The headers i9, 29, and 2! are also connected in series below the level of liquid refrigerant therein by liquid refrigerant equalizing passages 24 and 25, which are also formed between the sheets by indentations in exterior sheet it. A series of headers is thus formed about the upper edges of the evaporator it, these headers being arranged to occupy a minimum amount of the usual storage space within the evaporator it, while at the same time they provide ample header space for the separation of liquid and vaporized refrigerant. The headers l9 and 2!, which are located at the extremities of the series of headers thus formed, are connected by a tortuous refrigerant circulatory system including passages extending about the walls of the evaporator i i, the passages being formed between the sheets by indentations in the sheet i5. This system of passages includes the refrigerant circulatory passage 28, which communicates with the header it below the normal liquid level therein, and the refrigerant passage .Zl communicating with the header 2! below the normal liquid level therein. The passages 2t Cal and 21 are connected in series by a branched section made up of the parallel passages 28 and 29.

The sheets I5 and I8 are welded or otherwise secured together along their peripheral edges and between the refrigerant passages, and the sheets are then bent in a horizontal U-shape, thus forming three vertical side walls of a freezing compartment.

The vertical front edges of the sheets I5 and I6 are bent to form inwardly extending flanges 38 and 3I, reinforcing the side walls and providing a suitable support for freezing shelves Ma and MI). The flanges 38 and 3I are provided with pairs of ears 32, 33, and 34, 35, respectively. The two horizontal shelves Ma and I4!) within the evaporator I4 are each made of portions of sheet metal, such as steel or other heat conducting material. The lower shelf MD is made of two complementary sheets of metal 36 and 31. A sinuous indentation is formed in the lower sheet 31 thus providing a refrigerant circulatory passage 38 between the sheets for the lower shelf. The sheets 36 and 31 are welded or otherwise joined together along their peripheral edges and between the indentations formed therein. A supporting and reinforcing flange 39 is formed along the front edge of the lower shelf and is secured to the ears 33 and 35 on the flanges 38 and 3|, respectively, by bolts 48 and M, the rear end of the shelf being supported by conduits 48 and 49, and by a bracket 36a welded to the shelf and the rear wall of the evaporator. The upper shelf I4a is made of complementary sheets of metal 42 and 43, a sinuous indentation being formed in the lower sheet 43 to provide a refrigerant circulatory passage 44 between the sheets for the supper shelf. The refrigerant circulatory passage 44 has not been shown in Fig. 2 in order that the refrigerant circulatory system in the vertical walls of the evaporator may be more clearly viewed, the passage 44 is, however, clearly shown in Fig. 4. The sheets 42 and 43 are welded or otherwise secured together along their peripheral edges and between the indentations formed therein, the front edge of the shelf being provided with a reinforcing flange 45. The upper shelf I4a is supported atthe front thereof by securing the flange 45 by bolts 46 and 41 to the ears 32 and 34 on flanges 38 and 3|, respectively. The rear of the shelf 14a is supported by conduits I3 and 48, and by a bracket 42a welded to the shelf and the rear wall of the evaporator. An evaporator having a very pleasing and symmetrical appearance is thus provided while at the same time it is so sturdily constructed that it will withstand hard usage.

The headers I9, 28, and 2I are maintained, during normal operation of the machine, about half full of liquid refrigerant as indicated in Fig. 3, the headers and passages forming a refrigerant containing chamber in the walls of the evaporator I4. The refrigerant circulatory passages 38 and 44 in the shelves I41) and Ma, respectively, as well as the refrigerant circulatory passages 28; 21, 28, and 29in the side walls of the evaporator I4 are thus maintained flooded with liquid refrigerant. The liquid and vaporized refrigerant separate in the headers I9, 28, and 2|, the vaporized refrigerant accumulating above the level of the liquid refrigerant in the headers. The vaporized refrigerant accumulated in the headers 28 and 2I passes through the series pressure equalizing passages 22 and 23,- which are connected thereto above the normal liquid level therein, to the header I9 from which it returns to the motor driven compressor contained in the casing I8 and 29 pastthe injection points 58 and-5I.

the liquid refrigerant circulates through the pasthrough a suction line 53. The suction line 53 is connected to the header I9 above the-normal liquid level therein.

Liquid refrigerant from the liquid line I3 is supplied to the upper shelf refrigerant passage 44, which is connected in series with the sinuous,

refrigerant passage 38 in the lower shelf by the conduit 48. It will be noted that the liquid line I3 and the conduit 48 are connected to the ends of the passage 44 in the upper shelf I4a by embossments 44a and 44b, respectively, thus forming a support for the rear edge of the shelf as the conduits I3 and 48 extend through holes in the rear wall of the evaporator I4. After passing through the sinuous passage 38 in the lower shelf MD, the liquid refrigerant is discharged therefrom into a conduit 49. The conduits 48 and 49 extend through holes in the rear wall of the evaporator I 4 and are connected to the ends of the passage 38 in the lower shelf I4b by embossments 38a and 38b, respectively, thus forming a support for the rear edge of the shelf. Since the fresh incoming refrigerant supplied to the evaporator I4 is first circulated through the series connected passages 38 and 44, the shelves I41: and I 4b provide a sharp freezing zone in which trays of water or the like to be frozen may conveniently be supported.

Liquid refrigerant is injected from the conduit 49 through branched ends 58 and 5| thereof, into the parallel refrigerant circulatory passages 28 and 29. The upper portion of the conduit 49 and the branched ends 58 and 5I thereof are located in the passages 28 and 29, respectively, between the sheets I5 and I6, which form the vertical walls of the evaporator I4. The injection of liquid refrigerant from the ends 58 and 5| of the conduit 49 induces a positive circulation of liquid refrigerant about the vertical walls of the evaporator I4 through the passages'28 and 29 into the passage 2'! from which it is discharged into the header 2I as indicated by the arrows in Fig. 4. Such injection of liquid refrigerant from the ends 58 and 5| of the conduit 49 also induces a recirculation of liquid refrigerant from the headers I9, 28, and 2| connected in series by the refrigerant equalizing passages 24 and 25, through the passage26 and then through the passages 28 As sages 24- to 29, inclusive, it is partially vaporized by the absorption of heat from the food storage compartment 52 in which the evaporator I4 is located. Such vaporized refrigerant is carried along by the positively circulating liquid refrigerant in the path described, until it reaches one of the headers I9, 28, or 2| in which it is allowed to separate from the liquid refrigerant and accumulates above the surface thereof. It will thus be seen that I provide an eflicient arrangement for positively circulating and recirculating the liquid refrigerant contained in the evaporator I4 until it is vaporized by the absorption of heat.

The evaporator I4 is supported from the removable top wall of the food storage compartment 52 by bolts or other securing means extending through holes 54 in the inturned-ears 55 formed along the upper edge of the vertical walls of the evaporator I4. The lower'portion of the evaporator I4 provides a storage space surrounded on five sides by refrigerated walls, so that articles contained therein may be rapidly cooled or frozen. The upper portion of the evaporator I4 provides nearlyas effective anarrangement for rapid heat transfer as the storage space there provided is surrounded on four sides by refrigerated walls and since the top of 'the evaporator H is located closely adjacent the top wall of the compartment 52 there will be :only a limited circulation of warmer air downthrough the top of the evaporator. The surfaces of the evaporator are designed to adequately cool the food compartment 52.

By utilizing a plurality of headers I9, 20 and 2 I, ample space is provided for the separation of liquid and vaporized refrigerant in relatively quiet zones, so that any liquid refrigerant remaining in the headers may be efficiently recirculated through the walls of the evaporator 14 and thus effectively utilized. These headers are so distributed that they occupy a minimum of usable storage space within the enclosure formed by the evaporator i4.

While I have shown a particular embodiment of my invention in connection with a compression refrigerating machine, I do not desire my invention to be limited to the particular construction shown and described and I intend in the appended claims to cover all modifications within the spirit and scope of my invention.

What I claim as new and desire to secure by Letters Patent of the United States, is:

1. An evaporator of the fioodedtype for refrigerating machines comprising a plurality of headers, means including pressure equalizing passages for connecting said headers in series above the normal liquid levels therein, means including liquid refrigerant equalizing passages for connecting said headers in series below the normal liquid levels therein, means including a refrigerant circulatory passage communicating with one of said headers at one end and with another of said headers at its other end for containing liquid refrigerant, and means communicating with said circulatory passage remote from said headers for producing a recirculation of liquid refrigerant from said headers and through said circulatory passage.

2. An evaporator of the flooded type for'refrigerating machines comprising a series of headers, means including pressure equalizing passages for connecting said headers in series above the normal liquid levels therein, means including liquid refrigerant equalizing passages for connecting said headers in series below the normal liquid level therein, means including a tortuous refrigerant circulatory passage communicating at its opposite ends with the headers located at the extremities of said series of headers for containing liquid refrigerant, and means injecting liquid refrigerant into said refrigerant circulatorypassage intermediate its ends for inducing recirculation of liquid refrigerant through said series of headers and said refrigerant circulatory passage.

3. An evaporator of the flooded type for refrigerating machines comprising a series of headers, means including pressure equalizing passages for connecting said headers in series above the normal liquid levels therein, means including liquid refrigerant equalizing passages for connecting said headers in series below the normal liquid levels therein, means including a tortuous refrigerant circulatory passage communicating at its opposite ends with the headers located at the extremities of said series of headers for containing liquid refrigerant, said refrigerant circulatory passage including a branched section intermediate its ends providing a plurality of parallel circulatory passages, and means injecting liquid refrigerant into said parallel circulatory passages for inducing recirculation of liquid refrigerant through said series of headers and said refrigerant circulatory passage.

4. An evaporator of the flooded type for refrigerating machines comprising complementary sheet metal portions, means for joining said sheet metal portions together, at least one of said sheet metal portions having indentations therein forming a series of headers, at least one of said sheet metal portions having indentations therein forming pressure equalizing passages connecting said headers in series above the normal liquid levels therein and liquid refrigerant equalizing passages connecting said headers in series below the normal liquid levels therein, means including a refrigerant circulatory passage formed in at least one of said sheet metal portions and having one end communicating with one of said headers and its other end communicating with another of said headers for containing liquid refrigerant, and means communicating with said refrigerant circulatory passage remote from said headers for producing a recirculation of liquid refrigerant through said headers and through said refrigerant circulatory passage.

5. An evaporator of the flooded type for refrigerating machines comprising complementary sheet metal portions, means joining said sheet metal portions together, at least one of said sheet metal portions having indentations therein forming a series of headers, a least one of said sheet metal portions having indentations therein forming pressure equalizing passages connecting said headers in series above the normal liquid levels therein and liquid refrigerant equalizing passages connecting said headers in series below the normal liquid levels therein, at least one of said sheet metal portions also having indentations therein forming a tortuous refrigerant circulatory passage communicating at its opposite ends with the headers located at the extremities of said series of headers, and means injecting liquid refrigerant into said refrigerant circulatory passage intermediate its ends for inducing recirculation of liquid refrigerant through said series of headers and said refrigerant circulatory passage.

6. An evaporator of the flooded type for refrigerating machines comprising complementary sheet metal portions, means for joining said'sheet metal portions together, at least one of said sheet metal portions having indentations therein forming a series of headers, a least one of said sheet metal portions having indentations therein forming pressure equalizing passages connecting said headers in series above'the normal liquid levels there n and liquid refrigerant equalizing passages connecting said headers in series below the normal liquid levels therein, at least one of said sheet metal portions also having indentations therein forming a tortuous refrigerant circulatory passage communicating at its opposite ends with the headers located at the extremities of said series of headers, said refrigerant circulatory passage including a branched section intermediate its ends providing a plurality of parallel cir'culatory passages, and means injecting liquid refrigerant into said parallel circulatory passages for inducing recirculation of liqu d refrigerant through said series of headers and said refrigerant circulatory passage.

'7. An evaporator of the flooded type for refrigerating machines comprising complementarysheet metal portions forming three vertical walls .of a freezing compartment, means for securing said complementary sheet metal portions together, at least one of said sheet metal portion-s having indentations therein forming a header in each of said vertical walls, means including passages connecting said headers for equalizing the distribution of refrigerant in said headers, means including a tortuous refrigerant circulatory passage communicating with at least two of said headers for containing liquid refrigerant, and means injecting liquid refrigerant into said tortuous refrigerant passage for inducing recircula tion of liquid refrigerant from said headers through said tortuous passage.

8. An evaporator of the flooded type for refrigerating machines comprising complementary U-shaped sheet metal portions forming three vertical walls of a freezing compartment, means for securing said complementary sheet metal portions together, at least one of said sheet metal portions having indentations therein forming a header in each of said vertical walls, means including passages connecting said headers for equalizing the distribution of refrigerant in said headers, means including a tortuous refrigerant circulatory passage extending between said sheets and communicating with at least two of said headers for containing liquid refrigerant, and means injecting liquid refrigerant into said tortuous refrigerant passage for inducing recirculation of liquid refrigerant from said headers through said tortuous passage. I

.9. An evaporator of the flooded type for refrigerating machines comprising complementary U-shaped sheet metal portions forming three vertical walls of a freezing compartment, means for joining said sheet metal portions together, at least one of said sheet metal portions having indentations therein forming a header in each of said vertical walls, at least one of said sheet metal portions having indentations therein forming pressure equalizing passages connecting said headers in series above the normalliquid levels therein and liquid refrigerant equalizing passages connecting said headers in series below the normal liquid levels therein, means including a refrigerant circulatory passage formed in at least one of said sheet metal portions and having one end communicating with one of said headers and its other end communicating with another of said headers for containing liquid refrigerant, and means communicating with said refrigerant circulatory passage remote from said headers forproducing a recirculation of liquid refrigerant through said headers and through said refrigerant circulatory passage.

10. An evaporator of the flooded type for refrigerating machines comprising complementary U -shaped sheet metal portions forming three vertical walls of a freezing compartment. means for securing said complementary sheet metal portions together, at least one of said sheet metal portions having indentations therein forming a header in each of said vertical walls, at least one of said sheet metal portions having indentations therein forming pressure equalizing passages connecting said headers in series above the normal liquid levels and liquid refrigerant equalizing passages connecting said headers in series below the normal liquid levels therein, at least one of said sheet metal portions having indentations therein forming a tortuous refrigerant circulatory passage communicating at its opposite ends with the headers located at the extremities of said series of headers, and means injecting liquid refrigerant into said refrigerant circulatory passage intermediate its ends for inducing recirculation of liquid refrigerant through said series of headers and said refrigerant circulatory passage.

11. An evaporator of the flooded type for refrigcrating machines comprising complementary U- shaped sheet metal portions forming three vertical walls of a freezing compartment, means for securing said complementary sheet metal portions together, at least one of said sheet metal portions having indentations therein forming a header in each of said vertical walls, at least one of said sheet metal portions having indentations therein forming pressure equalizing passages connecting said headers in series above the normal liquid levels therein and liquid refrigerant equalizing passages connecting said headers in series below the normal liquid levels therein, at least one of said sheet metal portions having indentations therein forming a tortuous refrigerant circulatory passage communicating at its opposite ends with two of said headers located in opposite walls of said compartment, said refrigerant circulatory passage including a branched section intermediate its ends providing a plurality of parallel circulatory passages; and means injecting liquid refrigerant into said parallel circulatory passages for inducing the recirculation of liquid refrigerant through saidseries of headers and said refrigerant circulatory passage.

12. An evaporator of the flooded type for refrigerating machines comprising complementary U-shaped sheet metal portions forming three vertical walls of a freezing compartment, means for securing said complementary sheet metal portions together, at least one of said sheet metal portions having indentations therein forming a header in each of said vertical walls, at least one of said sheet metal portions having indentations therein forming pressure equalizing passages connecting said headers in series above the normal liquid levels therein and liquid refrigerant equalizing passages connecting said headers in series below the normal liquid levels therein, at least one of said sheet metal portions having indentations therein forming a tortuous refrigerant circulatory passage communicating at its opposite ends with headers located in opposite walls of said compartment, a shelf extending across said compartment, means including a refrigerant circulatory passage for cooling said shelf, and means injecting liquid refrigerant from said last mentioned passage into said first mentioned refrigerant circulatory passage intermediate the ends of the latter for inducing recirculation of liquid refrigerant through said series of headers and said first mentioned refrigerant circulatory passage.

13. An evaporator of the flooded type for refrigerating machines comprising complementary U-shaped sheet metal portions forming three vertical walls of a freezing compartment, means for securing said complementary sheet metal portions together, at least one of said sheet metal portions having indentations therein forming a header in each of said'vertical walls, at least one of said sheet metal portions having indentations therein forming pressure equalizing passages connecting said headers in series above the normal liquid levels therein and liquid refrigerant equalizing passages connecting said headers in series below the normal liquid levels therein, at least one of said Sheet metal portions having indentations therein fornung a tortuous refrigerant circulatory passage communicating at its opposite ends with headers located in opposite walls of said compartment, said refrigerant cir- -cu1atory passage including a branched section intermediate' its ends providing a plurality of parshelf to said sheet metal portions.

allel circulatory passages, a shelf extending across said compartment, means including a refrigerant circulatory passage for cooling said shelf, and means injecting liquid refrigerant from said last mentioned circulatory passage into said parallel circulatory passages for inducing recirculation of liquid refrigerant through said series of headers and said first mentioned refrigerant circulatory passage. g

14. An evaporator of the flooded type for refrigerating machines, comprising complementary sheet metal portions of a horizontal U-shaped 'form constituting three vertical walls of a-freezing compartment, means for securing said com- .plementary sheet metal portions together, at least one of said sheet metal portions having indentations therein forming refrigerant passages in said walls, a sheet metal shelf provided with a refrigerant circulatory passage extending across said compartment, and means for securing said 15. An evaporator of the flooded type for refrigerating machines comprising complementary sheet metal portions of a horizontal U-shaped form constituting three vertical walls of a freezing compartment. means for securing said complementary sheet metal portions together, at least one of said sheet metal portions having indentations therein forming a tortuous refrigerant passage extending about said walls, said sheet metal portions being provided with inturned flanges along the vertical edges thereof, a sheet metal shelf provided with a refrigerant circulatory passage extending across said compartment, and means for securing said shelf to said inturned flanges.

16. An evaporator of the flooded type for refrigerating machines comprising complementary sheet metal portions of a horizontal U-shaped form constituting three vertical walls of a freezing compartment, means for securing said complementary sheet metal portions together, at least one of said sheet metal portions having indentations therein forming a tortuous refrigerant passage extending about said walls, said sheet metal portions being provided. with inturned flanges along the vertical edges thereof, a plurality of vertically spaced sheet metal shelves provided witli' refrigerant circulatory passages extending across said compartment, and means for circulating liquid refrigerant through said passages in said shelves in series and then injecting the same in said first mentioned tortuous refrigerant passage.

FRANK T. GROTH-OUSE.

' CERTIFICATE OF CORRECTION.

Patent No.- 2,064,659. December 15, 1936.

FRANK T. GROTHDUSE.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 3, second coIumn, lines- 31 and 53, claims 5 and 6 respectively, for the article "a." second occurrence, read at; and that the said Letters Patent should be read with these corrections therein that the same may conform to the record of the case in the Patent Office. I

Signed and sealed this 23rd day of February, A. D. 1937.

e Henry Van Arsdale (Seal) Acting Commissioner of Patents. 

